1. Field of the Invention
This invention relates to a locking structure of a short-circuit contact for a connector having a connections sensor usable as a connector in an air bag system mainly installed in a motor vehicle.
2. Description of the Prior Art
A terminal of a connector has been secured generally by providing an upraised portion integrally at the terminal and engaging the terminal with a bottom wall of a terminal receiving chamber of a connector housing or engaging a flexible lock arm, which is formed integrally on a ceiling wall of the terminal receiving chamber, with the terminal at a shoulder or a hole of an electric contact thereof.
However, since the upraised lock arm has been easily damaged because of the smallness of its size, and has disadvantages such as an easy drop out of the terminal, poor contacting and the like.
Therefore, a connector K having a double locking structure, as shown in FIGS. 7 and 8, has been proposed in Japanese Patent Application Laid Open No. 4-23391.
The connector K disclosed in the above publication has the double locking structure in which a lock arm d provided at the interior of a terminal receiving chamber b is engaged with a locking hole e of a terminal c contained in the terminal receiving chamber b of a connector housing a to provide a primary locking, then an insert pin f is inserted into the connector housing a in a vertical direction, and then a protrusion g of the insert pin f is engaged with a locking portion h of the terminal c to provide a secondary locking.
On the other hand, the applicant of the present patent application has already proposed, in a Japanese Patent Application Ser. No. 5-289153, a connector K' having a connection sensor shown in FIG. 9 as a connector adapted for use in an air bag system to be installed in a motor vehicle.
The connector K' has a short-circuit contact j shown in FIG. 10 which is mounted at one connector housing i, and a pair of connection sensing terminals m which are contained at the other connector housing k.
As shown in FIG. 11, when the connector housing i is insufficiently engaged with the connector housing k, the short-circuit contact j is bent as being pressed by a locking arm o of the connector housing i, and the short-circuit contact j is not brought into contact with the pair of connection sensing terminals m, thereby the pair of connection sensing terminals m are held at a state of cut-off.
As shown in FIG. 12, when the connector housing i is completely engaged with the connector housing k, the lock arm o is returned to its original position, and the short-circuit contact j, FIG. 19 is brought into contact with the pair of connection sensing terminals m. As a result, since the pair of connection sensing terminals m, m are electrically conducted with each other through the short-circuit contact j, the engagement of the connector housing i and the connector housing k is detected by detecting said conduction of the pair of connection sensing terminals by means of an electric circuit.
However, in the connector K', FIG. 9, described above, the means for fastening the short-circuit contact j on the connector housing i is provided only by engaging the coupling protrusion n at the side of the short-circuit contact j with a coupling portion provided at the connector housing i. Therefore, the short-circuit contact j has disadvantages such that it is easily removed from the connector housing i and then making it impossible to detect the engagement of the connector housings, and this results in a decrease of reliability. Accordingly, even if the locking structure of the insert pin f, FIG. 7, of said connector K is intended to use in the short-circuit contact j in order to fasten it firmly, there is a problem such that the application of the insert pin f is practically difficult due to a structural problem of the connector housing i for use in the air bag system.